Botanical classification: Calibrachoa sp. 
Variety denomination: xe2x80x98Kakegawa S51xe2x80x99.
xe2x80x98Kakegawa S51xe2x80x99 originated from a hybridization made in November 1998 in Kakegawa, Japan. The female parent was a Calibrachoa breeding line with red colored flowers and erect habit known as K7-1172. The male parent was Calibrachoa breeding line with white flowers and a ring at the corolla throat and creeping plant habit known as 97-1101 -1.
In February 1999, F1 seed was sown from this cross and 30 plants were transplanted to outdoors. Three plants were selected and intercrossed to produce F2 seed. In August 1999 the second generation seed was planted in the field at Kakegawa and plants with different shades of pink flowers and white and pink flowers with or without corolla throat markings were observed. One plant line was selected for its dark pink flowers, red corolla throat and yellow corolla tube. The selection was vegetatively propagated again in February 2000 and evaluated in greenhouses in Japan.
The breeder selected one line, for its flower color and abundance, to be vegetatively propagated and further evaluated in Salinas, Calif. during 2001. This selection was subsequently named xe2x80x98Kakegawa S51xe2x80x99 and was determined to have its trait characteristics firmly fixed.